British and U.S. intelligence had no credible evidence of a link between Saddam Hussein and the Sept. 11, 2001, attacks on the United States before the 2003 Iraq invasion, the ex-head of Britain's domestic spy agency told the country's inquiry into the war Tuesday.

Eliza Manningham-Buller, director of the MI5 between 2002 and 2007, said that nothing to connect the attacks to Baghdad was discovered ahead of the 2003 invasion of Iraq. The ex-spy chief also said the war caused allies to lose focus on the al-Qaida threat in Afghanistan, emboldened Osama bin Laden and led to the radicalization of a generation of homegrown British extremists.

Manningham-Buller said those pushing the case for war in the United States gave undue prominence to scraps of inconclusive intelligence on possible links between Iraq and the 2001 attacks, singling out the then-U.S. Defense Secretary Donald Rumsfeld.

"There was no credible intelligence to suggest that connection and that was the judgment, I might say, of the CIA," she told the inquiry. "It was not a judgment that found favor with some parts of the American machine."

She suggested the dispute led Rumsfeld to disregard CIA intelligence in favor of work produced by his own department.

"It is why Donald Rumsfeld started an alternative intelligence unit in the Pentagon to seek an alternative judgment," said Manningham-Buller, who was a frequent visitor to the U.S. as MI5 chief. "To my mind, Saddam Hussein had nothing to do with 9/11 and I have never seen anything to make me change my mind."